Profile
Settings
Refer your friends
Sign out
The phrase “biodiversity” refers to the great diversity of life on Earth. It can also be used to refer to all of the species in a certain location or environment. Plants, microorganisms, animals, and humans are all considered part of biodiversity. According to scientists, there are around 8.7 million plant and animal species on the planet. However, only about 1.2 million species have been recognised and described to date, with the majority of them being insects. This indicates that the existence of millions of other creatures is unknown.
If environmental changes occur, a uniform population of a single species of plant acclimated to a certain habitat is more vulnerable. A population with a greater diversity of plant species has a better chance of containing individuals who can adapt to changes in the environment.
Measurement of Biodiversity Index
On environmental issues, a variety of indicators have been used. The Living Planet Index (LPI), Ecological Footprint (EF), City Development Index (CDI), Human Development Index (HDI), Environmental Sustainability Index (ESI), Environmental Performance Index (EPI), Environmental Vulnerability Index (EVI), Index of Sustainable Economic Welfare/Genuine Progress Index (ISEW/GPI), Well-Being Index (WI), Genuine Savings Index (GS), and Environmental Adjusted Domestic Product (EADP) are the indicators (EDP). The most recent is less well-known, but it is gaining traction after Singapore was named to the City Biodiversity Index.
It would be simpler to calculate the Biodiversity Index if biodiversity could be assessed in terms of the number of birds in a forest, wildflowers in a meadow, or beetles in a log. Unfortunately, one of the benefits of biodiversity is simplicity. Ecosystems are far more complicated than we can comprehend. A prevalent misunderstanding is that biodiversity is synonymous with species diversity, and that more species in a given area equals higher biodiversity.
Species Richness
Richness R just counts how many different kinds are present in the dataset of interest. The number of various species in the associated species list, for example, is the species richness (typically denoted S) of a dataset. Because richness is a straightforward metric, it has become a common diversity index in ecology, where abundance data for the datasets of interest is frequently unavailable. Because richness does not take into consideration the abundances of the types, it is not the same as diversity, which does. However, if true diversity is calculated with q = 0, the effective number of types (D) equals the actual number of types (R).
Shannon and Simpson Indexes
The Shannon index, also known as Shannon’s diversity index, Shannon–Wiener index, Shannon–Weaver index, and Shannon entropy, has been a popular diversity measure in ecological literature. Claude Shannon first suggested the measure to estimate the entropy (uncertainty or information content) in text strings. The concept is that the more different letters there are in the string of interest, and the more evenly their proportionate abundances are distributed, the more difficult it is to correctly forecast which letter will come next.
The Shannon entropy measures the degree of surprise or entropy associated with this prediction. It’s usually calculated like this:
where pi is the proportion of characters in the string of interest that belong to the i-th type of letter. In ecology, pi refers to the proportion of individuals in a dataset who belong to the i-th species. The Shannon entropy then measures the uncertainty in predicting the species identity of a randomly selected individual from the dataset. The base of the logarithm used to calculate the Shannon entropy can be chosen arbitrarily, even though the equation is stated with natural logarithms. Shannon discussed the logarithm bases 2, 10, and e, which have subsequently become the most prevalent bases in Shannon entropy applications.
Since this mean proportionate abundance of the kinds grows as the number of types decreases and the abundance of the most abundant type increases, λ acquires small values in high-diversity datasets and large values in low-diversity datasets. Because this is contradictory behaviour for a diversity index, transformations of λ that grow with increasing diversity have frequently been utilised instead.
The inverse Simpson index (1/λ) and the Gini–Simpson index have been the most popular of these indices (1 – λ). Both of these indices have been referred to as the Simpson index in the ecological literature, therefore it’s important not to compare them as if they’re the same. The diversity (D) formula is as follows:
Where N is the total number of stated species residing in the same area and n is the abundance of the i-th species in an area.
Conclusion
Biodiversity, short for biological diversity, is a phrase that refers to the diversity of life on Earth as well as the interactions between living organisms. Individuals (genetic variety), species (number of species), and ecosystems are all examples of diversity (variations in ecosystems).
